Many machines and vehicles, and in particular motorcycles employ handlebars as a controlling means or device. Typically the handlebars are made of metal and usually tubular steel is used. Handlebar grips have been used in the past to alleviate many of the problems associated with handlebar usuage.
The use of handlebars on high powered, high speed vehicles or other machinery requires that the operator maintain a firm grip on the handlebar. The surface of the handlebars often has a very slick chrome plated finish and is almost always very smooth. This slick smooth surface can cause a loss of grip if the operator's palms become moist or dirty. To prevent this occurrence, handlebar grips have been used. Typically, the handlebar grips are made of a hard rubber or hard polymer material formed in a hollow cylindrical shape which can be hand pressed over the ends of the handlebars. The traction of the inside surface of the polymer tubular structure prevents the handlebar grip from slipping off the handlebar, thus, permitting the operator to retain better control of the machine by grasping the handlebar securely using the handlebar grip.
Other problems associated with the use of handlebars include discomfort caused by grasping a hot or cold steel handlebar. This problem too has generally been overcome by the prior art handlebar grip which tends to insulate the operator's hand from the cold metallic surface on winter mornings or alternately from the hot metallic surface when the handlebar has been sitting in the sun. Also, the handlebars may be manufactured with rough or jagged ends which can cause injury to the operator. To alleviate this problem the prior art handlebar grips are formed with one end closed so that it abuts against the end of the handlebar thereby covering any possible jagged edges left during the manufacture of the handlebar. To provide adequate protection and to prevent slipping, the handlebar grips have of necessity been formed of durable hard polymer material.
Another problem with prior art handlebar grips is the problem of fatigue to the hand caused by continuous vibrations transmitted from the machine through the handlebars. Particularly in the use of motorcycles, the operator's hands are subjected to continuous high frequency vibration caused by reciprocating engines which operate at high rpm's. The effect of this vibration transmitted to the operator through the hard rubber handlebar grip can be fatigue and numbing of the hands and fingers. This situation is potentially dangerous especially to the operators of high speed vehicles such as motorcycles with inherent characteristics requiring hands on the controls at all times. Another unsolved problem relates to wear and tear and weather deterioration of the exterior surface of the handlebar grips. Such wear characteristics are further exacerbated by the user constantly gripping and rubbing the handlebar grips. Prior art attempts to alleviate the fatigue problem have included such items as flexible ribs formed on the outer surface of the hard rubber grip. These ribs are particularly susceptible to wear because of the reduced surface area and the reduced durability of the flexible ribs which come in contact with the operator's hands. The result has been accelerated wearing of the handlebar grips requiring frequent expensive replacement. These problems were solved by the inventive handlebar grip set forth in commonly assigned copending patent application Ser. No. 319,898 filed Nov. 10, 1981 and entitled Handlebar Grip.
In the commonly assigned copending application, a handlebar grip was disclosed in which a shock absorber layer was provided for overlaying a body member handlebar grip to reduce hand fatigue and shock and means were included for replaceably attaching the shock absorbent layer to the body member.
However, the constant turning and gripping of the shock absorber layer may cause it to slip both longitudinally and circumferentially with respect to the body members. This slipping causes abnormal wear and requires accelerated replacement of the shock absorber layer.